Expediting projects in PERT with stochastic time estimates
Unlike deterministic PERT networks, which use single time estimates and assume that all time estimates involve no uncertainty, stochastic PERT networks assume time estimates are inherently uncertain. This article examines the problems involved in developing a rationale for expediting--also known as crashing--stochastic networks. In doing so, it describes possible rules for expediting and the inadequacy of PERT techniques when used for determining critical paths in stochastic networks. It explains the function of network expediting, the development of PERT (Program Evaluation and Review Technique) in relation to the critical path method (CPM), the purpose of PERT, the reasons CPM rules are unsuited for PERT, and the problems with alternative procedures for calculating path length. It then details three rules for expediting projects and discusses these in relation to stochastic time estimates.